<script setup lang="ts">
import { ref, watch } from 'vue'

const count = ref(0)

/**
 * Challenge 1: Watch once
 * Make sure the watch callback only triggers once
 */
const stop = watch(count, () => {
  console.log('Only triggered once')
  stop()
})

count.value = 1
setTimeout(() => count.value = 2)

/**
 * Challenge 2: Watch object
 * Make sure the watch callback is triggered
 */
const state = ref({
  count: 0,
})

// watch(state.value, () => {
//   console.log('The state.count updated')
// })
watch(state, () => {
  console.log('The state.count updated')
}, { deep: true })

state.value.count = 2

/**
 * Challenge 3: Callback Flush Timing
 * Make sure visited the updated eleRef
 */

const eleRef = ref()
const age = ref(2)
watch(age, () => {
  console.log(eleRef.value)
}, { flush: 'post' })
age.value = 18
</script>

<template>
  <div>
    <p>
      {{ count }}
    </p>
    <p ref="eleRef">
      {{ age }}
    </p>
  </div>
</template>
